Parse CSV to Kotlin List

I'm a bit confused.
I have this csv line with double quote("") as grouped strings, and want to convert to Kotlin List.
However it produces a single array with size 1.
I want to be able to get the group, assumes at position 2.

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)")

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

This gives me error

java.lang.IndexOutOfBoundsException: Index: 2, Size: 1

asked Jan 1 at 18:04

luca ditrimma

7119

What is your expected result?

– forpas
Jan 1 at 18:08

"Subject 1, Subject 2, Subject 3"

– luca ditrimma
Jan 1 at 18:09

Isn't the delimeter " in this case?

– forpas
Jan 1 at 18:17

add a comment |

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)")

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

This gives me error

java.lang.IndexOutOfBoundsException: Index: 2, Size: 1

asked Jan 1 at 18:04

luca ditrimma

7119

What is your expected result?

– forpas
Jan 1 at 18:08

"Subject 1, Subject 2, Subject 3"

– luca ditrimma
Jan 1 at 18:09

Isn't the delimeter " in this case?

– forpas
Jan 1 at 18:17

add a comment |

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)")

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

This gives me error

java.lang.IndexOutOfBoundsException: Index: 2, Size: 1

asked Jan 1 at 18:04

luca ditrimma

7119

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)")

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

This gives me error

java.lang.IndexOutOfBoundsException: Index: 2, Size: 1

kotlin

asked Jan 1 at 18:04

luca ditrimma

7119

asked Jan 1 at 18:04

luca ditrimma

7119

asked Jan 1 at 18:04

luca ditrimma

7119

asked Jan 1 at 18:04

luca ditrimma

7119

asked Jan 1 at 18:04

luca ditrimma

7119

What is your expected result?

– forpas
Jan 1 at 18:08

"Subject 1, Subject 2, Subject 3"

– luca ditrimma
Jan 1 at 18:09

Isn't the delimeter " in this case?

– forpas
Jan 1 at 18:17

add a comment |

What is your expected result?

– forpas
Jan 1 at 18:08

"Subject 1, Subject 2, Subject 3"

– luca ditrimma
Jan 1 at 18:09

Isn't the delimeter " in this case?

– forpas
Jan 1 at 18:17

What is your expected result?

– forpas
Jan 1 at 18:08

"Subject 1, Subject 2, Subject 3"

– luca ditrimma
Jan 1 at 18:09

Isn't the delimeter " in this case?

– forpas
Jan 1 at 18:17

add a comment |

4 Answers
4

active

oldest

votes

The given regex just works fine. Currently you try to split the string s at the raw regex as delimeter, which does not exists in s. Simply add .toRegex() to the regex.

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)".toRegex())

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

answered Jan 1 at 20:56

pixix4

3311311

this work like charm!

– luca ditrimma
Jan 2 at 0:57

add a comment |

Split by " and you get a list with size = 3

and what you need is at index = 1.

Then you need to split the item index = 0 by , for the name and the number:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val list: List<String> = s.split(""")

val listStart = list[0].split(",")

val subjects = list[1].trim()

val name = listStart[0].trim()

val number = listStart[1].trim()

Another way if you don't really need the list but only the values:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val subjects = s.substringAfter(""").substringBefore(""").trim()

val name = s.substringBefore(",").trim()

val number = s.substringAfter(",").substringBefore(",").trim()



println("name: " + name)

println("number: " + number)

println("subjects: " + subjects)

will print:

name: John Doe

number: 13

subjects:Subject 1, Subject 2, Subject 3

edited Jan 1 at 19:57

answered Jan 1 at 18:20

forpas

16.4k3627

This only works if the fields don't contain the separator though

– EpicPandaForce
Jan 1 at 18:23

Which separator?

– forpas
Jan 1 at 18:24

thanks forpas, how to get John Doe at 0, 13 at 1 and Subjects at 2? I assume the field is separated by comma.

– luca ditrimma
Jan 1 at 18:33

See my edited answer

– forpas
Jan 1 at 18:40

Your solution worked. But, is there any other solution which use comma as separator and consider double quote as one grouped value?

– luca ditrimma
Jan 1 at 18:51

|
show 1 more comment

I'd recommend not doing the parsing yourself, but using an existing library. (For example, I found Apache Commons CSV easy to use from Kotlin.)

Although writing parsing code can be fun, and CSV seems simple enough, it has enough complications and variations that unless you created it yourself, you're likely to miss some cases. (Not just escaped quotes, but other escaped characters, nested quotes, fields which include newlines, comment lines… And my favourite gotcha: MS Excel uses the machine's list separator, which can be semicolon or another character instead of comma to separate fields!)

Trust me, I've been there…

answered Jan 1 at 21:41

gidds

1,093127

this csv is created by me from another app. :-) Btw, I will give a look on your suggestion for future upgrade.

– luca ditrimma
Jan 1 at 23:59

add a comment |

Is this helpful? Not much of a test since I make no actual assertions, but maybe enough to put you onto the idea.

@Test

fun should_tolerate_quoted_commas_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val pattern = Pattern.compile(",")

    s.split(regex=pattern, limit=3).forEach( System.out::println )

}

output:

John Doe

 13

 "Subject 1, Subject 2, Subject 3"

EDIT 1:

Similarly...

@Test

fun should_make_list_from_quoted_string_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val outerList = s.split(regex = Pattern.compile(","), limit = 3)

    outerList[2].replace(""","").split(",").forEach( System.out::println )

}

edited Jan 1 at 22:11

answered Jan 1 at 19:25

unigeek

1,7021419

add a comment |

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4 Answers
4

active

oldest

votes

4 Answers
4

active

oldest

votes

The given regex just works fine. Currently you try to split the string s at the raw regex as delimeter, which does not exists in s. Simply add .toRegex() to the regex.

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)".toRegex())

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

answered Jan 1 at 20:56

pixix4

3311311

this work like charm!

– luca ditrimma
Jan 2 at 0:57

add a comment |

The given regex just works fine. Currently you try to split the string s at the raw regex as delimeter, which does not exists in s. Simply add .toRegex() to the regex.

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)".toRegex())

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

answered Jan 1 at 20:56

pixix4

3311311

this work like charm!

– luca ditrimma
Jan 2 at 0:57

add a comment |

The given regex just works fine. Currently you try to split the string s at the raw regex as delimeter, which does not exists in s. Simply add .toRegex() to the regex.

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)".toRegex())

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

answered Jan 1 at 20:56

pixix4

3311311

The given regex just works fine. Currently you try to split the string s at the raw regex as delimeter, which does not exists in s. Simply add .toRegex() to the regex.

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

var list: List<String> = s.split(",(?=([^"]*"[^"]*")*[^"]*$)".toRegex())

Log.d("size:", list.size.toString() + " - subjects:" + list[2])

answered Jan 1 at 20:56

pixix4

3311311

answered Jan 1 at 20:56

pixix4

3311311

answered Jan 1 at 20:56

pixix4

3311311

answered Jan 1 at 20:56

pixix4

3311311

this work like charm!

– luca ditrimma
Jan 2 at 0:57

add a comment |

this work like charm!

– luca ditrimma
Jan 2 at 0:57

this work like charm!

– luca ditrimma
Jan 2 at 0:57

add a comment |

Split by " and you get a list with size = 3

and what you need is at index = 1.

Then you need to split the item index = 0 by , for the name and the number:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val list: List<String> = s.split(""")

val listStart = list[0].split(",")

val subjects = list[1].trim()

val name = listStart[0].trim()

val number = listStart[1].trim()

Another way if you don't really need the list but only the values:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val subjects = s.substringAfter(""").substringBefore(""").trim()

val name = s.substringBefore(",").trim()

val number = s.substringAfter(",").substringBefore(",").trim()



println("name: " + name)

println("number: " + number)

println("subjects: " + subjects)

will print:

name: John Doe

number: 13

subjects:Subject 1, Subject 2, Subject 3

edited Jan 1 at 19:57

answered Jan 1 at 18:20

forpas

16.4k3627

This only works if the fields don't contain the separator though

– EpicPandaForce
Jan 1 at 18:23

Which separator?

– forpas
Jan 1 at 18:24

thanks forpas, how to get John Doe at 0, 13 at 1 and Subjects at 2? I assume the field is separated by comma.

– luca ditrimma
Jan 1 at 18:33

See my edited answer

– forpas
Jan 1 at 18:40

Your solution worked. But, is there any other solution which use comma as separator and consider double quote as one grouped value?

– luca ditrimma
Jan 1 at 18:51

|
show 1 more comment

Split by " and you get a list with size = 3

and what you need is at index = 1.

Then you need to split the item index = 0 by , for the name and the number:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val list: List<String> = s.split(""")

val listStart = list[0].split(",")

val subjects = list[1].trim()

val name = listStart[0].trim()

val number = listStart[1].trim()

Another way if you don't really need the list but only the values:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val subjects = s.substringAfter(""").substringBefore(""").trim()

val name = s.substringBefore(",").trim()

val number = s.substringAfter(",").substringBefore(",").trim()



println("name: " + name)

println("number: " + number)

println("subjects: " + subjects)

will print:

name: John Doe

number: 13

subjects:Subject 1, Subject 2, Subject 3

edited Jan 1 at 19:57

answered Jan 1 at 18:20

forpas

16.4k3627

This only works if the fields don't contain the separator though

– EpicPandaForce
Jan 1 at 18:23

Which separator?

– forpas
Jan 1 at 18:24

thanks forpas, how to get John Doe at 0, 13 at 1 and Subjects at 2? I assume the field is separated by comma.

– luca ditrimma
Jan 1 at 18:33

See my edited answer

– forpas
Jan 1 at 18:40

Your solution worked. But, is there any other solution which use comma as separator and consider double quote as one grouped value?

– luca ditrimma
Jan 1 at 18:51

|
show 1 more comment

Split by " and you get a list with size = 3

and what you need is at index = 1.

Then you need to split the item index = 0 by , for the name and the number:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val list: List<String> = s.split(""")

val listStart = list[0].split(",")

val subjects = list[1].trim()

val name = listStart[0].trim()

val number = listStart[1].trim()

Another way if you don't really need the list but only the values:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val subjects = s.substringAfter(""").substringBefore(""").trim()

val name = s.substringBefore(",").trim()

val number = s.substringAfter(",").substringBefore(",").trim()



println("name: " + name)

println("number: " + number)

println("subjects: " + subjects)

will print:

name: John Doe

number: 13

subjects:Subject 1, Subject 2, Subject 3

edited Jan 1 at 19:57

answered Jan 1 at 18:20

forpas

16.4k3627

Split by " and you get a list with size = 3

and what you need is at index = 1.

Then you need to split the item index = 0 by , for the name and the number:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val list: List<String> = s.split(""")

val listStart = list[0].split(",")

val subjects = list[1].trim()

val name = listStart[0].trim()

val number = listStart[1].trim()

Another way if you don't really need the list but only the values:

val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

val subjects = s.substringAfter(""").substringBefore(""").trim()

val name = s.substringBefore(",").trim()

val number = s.substringAfter(",").substringBefore(",").trim()



println("name: " + name)

println("number: " + number)

println("subjects: " + subjects)

will print:

name: John Doe

number: 13

subjects:Subject 1, Subject 2, Subject 3

edited Jan 1 at 19:57

answered Jan 1 at 18:20

forpas

16.4k3627

edited Jan 1 at 19:57

answered Jan 1 at 18:20

forpas

16.4k3627

answered Jan 1 at 18:20

forpas

16.4k3627

answered Jan 1 at 18:20

forpas

16.4k3627

This only works if the fields don't contain the separator though

– EpicPandaForce
Jan 1 at 18:23

Which separator?

– forpas
Jan 1 at 18:24

thanks forpas, how to get John Doe at 0, 13 at 1 and Subjects at 2? I assume the field is separated by comma.

– luca ditrimma
Jan 1 at 18:33

See my edited answer

– forpas
Jan 1 at 18:40

Your solution worked. But, is there any other solution which use comma as separator and consider double quote as one grouped value?

– luca ditrimma
Jan 1 at 18:51

|
show 1 more comment

This only works if the fields don't contain the separator though

– EpicPandaForce
Jan 1 at 18:23

Which separator?

– forpas
Jan 1 at 18:24

thanks forpas, how to get John Doe at 0, 13 at 1 and Subjects at 2? I assume the field is separated by comma.

– luca ditrimma
Jan 1 at 18:33

See my edited answer

– forpas
Jan 1 at 18:40

Your solution worked. But, is there any other solution which use comma as separator and consider double quote as one grouped value?

– luca ditrimma
Jan 1 at 18:51

This only works if the fields don't contain the separator though

– EpicPandaForce
Jan 1 at 18:23

Which separator?

– forpas
Jan 1 at 18:24

thanks forpas, how to get John Doe at 0, 13 at 1 and Subjects at 2? I assume the field is separated by comma.

– luca ditrimma
Jan 1 at 18:33

See my edited answer

– forpas
Jan 1 at 18:40

Your solution worked. But, is there any other solution which use comma as separator and consider double quote as one grouped value?

– luca ditrimma
Jan 1 at 18:51

|
show 1 more comment

I'd recommend not doing the parsing yourself, but using an existing library. (For example, I found Apache Commons CSV easy to use from Kotlin.)

Trust me, I've been there…

answered Jan 1 at 21:41

gidds

1,093127

this csv is created by me from another app. :-) Btw, I will give a look on your suggestion for future upgrade.

– luca ditrimma
Jan 1 at 23:59

add a comment |

I'd recommend not doing the parsing yourself, but using an existing library. (For example, I found Apache Commons CSV easy to use from Kotlin.)

Trust me, I've been there…

answered Jan 1 at 21:41

gidds

1,093127

this csv is created by me from another app. :-) Btw, I will give a look on your suggestion for future upgrade.

– luca ditrimma
Jan 1 at 23:59

add a comment |

I'd recommend not doing the parsing yourself, but using an existing library. (For example, I found Apache Commons CSV easy to use from Kotlin.)

Trust me, I've been there…

answered Jan 1 at 21:41

gidds

1,093127

I'd recommend not doing the parsing yourself, but using an existing library. (For example, I found Apache Commons CSV easy to use from Kotlin.)

Trust me, I've been there…

answered Jan 1 at 21:41

gidds

1,093127

answered Jan 1 at 21:41

gidds

1,093127

answered Jan 1 at 21:41

gidds

1,093127

answered Jan 1 at 21:41

gidds

1,093127

this csv is created by me from another app. :-) Btw, I will give a look on your suggestion for future upgrade.

– luca ditrimma
Jan 1 at 23:59

add a comment |

this csv is created by me from another app. :-) Btw, I will give a look on your suggestion for future upgrade.

– luca ditrimma
Jan 1 at 23:59

this csv is created by me from another app. :-) Btw, I will give a look on your suggestion for future upgrade.

– luca ditrimma
Jan 1 at 23:59

add a comment |

Is this helpful? Not much of a test since I make no actual assertions, but maybe enough to put you onto the idea.

@Test

fun should_tolerate_quoted_commas_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val pattern = Pattern.compile(",")

    s.split(regex=pattern, limit=3).forEach( System.out::println )

}

output:

John Doe

 13

 "Subject 1, Subject 2, Subject 3"

EDIT 1:

Similarly...

@Test

fun should_make_list_from_quoted_string_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val outerList = s.split(regex = Pattern.compile(","), limit = 3)

    outerList[2].replace(""","").split(",").forEach( System.out::println )

}

edited Jan 1 at 22:11

answered Jan 1 at 19:25

unigeek

1,7021419

add a comment |

Is this helpful? Not much of a test since I make no actual assertions, but maybe enough to put you onto the idea.

@Test

fun should_tolerate_quoted_commas_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val pattern = Pattern.compile(",")

    s.split(regex=pattern, limit=3).forEach( System.out::println )

}

output:

John Doe

 13

 "Subject 1, Subject 2, Subject 3"

EDIT 1:

Similarly...

@Test

fun should_make_list_from_quoted_string_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val outerList = s.split(regex = Pattern.compile(","), limit = 3)

    outerList[2].replace(""","").split(",").forEach( System.out::println )

}

edited Jan 1 at 22:11

answered Jan 1 at 19:25

unigeek

1,7021419

add a comment |

Is this helpful? Not much of a test since I make no actual assertions, but maybe enough to put you onto the idea.

@Test

fun should_tolerate_quoted_commas_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val pattern = Pattern.compile(",")

    s.split(regex=pattern, limit=3).forEach( System.out::println )

}

output:

John Doe

 13

 "Subject 1, Subject 2, Subject 3"

EDIT 1:

Similarly...

@Test

fun should_make_list_from_quoted_string_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val outerList = s.split(regex = Pattern.compile(","), limit = 3)

    outerList[2].replace(""","").split(",").forEach( System.out::println )

}

edited Jan 1 at 22:11

answered Jan 1 at 19:25

unigeek

1,7021419

Is this helpful? Not much of a test since I make no actual assertions, but maybe enough to put you onto the idea.

@Test

fun should_tolerate_quoted_commas_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val pattern = Pattern.compile(",")

    s.split(regex=pattern, limit=3).forEach( System.out::println )

}

output:

John Doe

 13

 "Subject 1, Subject 2, Subject 3"

EDIT 1:

Similarly...

@Test

fun should_make_list_from_quoted_string_in_third_column() {

    val s = "John Doe, 13, "Subject 1, Subject 2, Subject 3""

    val outerList = s.split(regex = Pattern.compile(","), limit = 3)

    outerList[2].replace(""","").split(",").forEach( System.out::println )

}

edited Jan 1 at 22:11

answered Jan 1 at 19:25

unigeek

1,7021419

edited Jan 1 at 22:11

answered Jan 1 at 19:25

unigeek

1,7021419

answered Jan 1 at 19:25

unigeek

1,7021419

answered Jan 1 at 19:25

unigeek

1,7021419

add a comment |

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